#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<assert.h>
char* My_strcat(char* str, const char*str1)
{
	assert(str1 != NULL);
	assert(str != NULL);
	char* ret = str;
	while (*str != '\0')
	{
		str++;
	}
	while (*(str++) = *(str1++));

	return ret;
}
int main()
{
	char ch1[20] = "hello";
	char ch2[] = "world";
	 My_strcat(ch1, ch2);
	 printf("%s\n", ch1);
	system("pause");
	return 0;
}
